9.7 Meter Triple Axle 1979 Avion Floor Rebuilding

[peyman.tavakolrad]

Hello everyone.
This year I bought this Trailer and by looking at I really wanted to build it from ground up. I have gutted this trailer out almost completely I started to remove the flooring which was made like a sandwich (thin plywood, hard foam, plywood) and the floor frame is connected with rivets to the shell all the way around. The whole floor sits on the frame .95% of the flooring is gone except for some of the framing that are connected to the shell I was wondering do I need to lift the shell before removing the rest of the frame or can I just removed the floor and replace it with out doing so?


Thank you. I will post some photos later today.

[peyman.tavakolrad]

It looks to me like the shell is sitting on those bars and other previous floor. I'm afraid the shell would come crashing down

[Jason]

I am redoing the floor in my 79 8.5 Meter. If your indenting the remaining wood to lift with the shell I'd be sure to make sure all the aluminum that transitions between the belly pan and the shell is free from the wood. There are allot of staples, screws, nails, etc that attach the wood to the transition pieces. Also you'll want to make sure all the elevator bolts are removed. There is also the wiring but that may be more obvious. There are probably more things to do as well. I'm replacing my floor without lifting the shell.
--Jason

[Salty]

What is written below is a work in progress. It is incomplete, but it would seem that it may be of help to you now. I make no apologies for its in-completion - (no photos yet etc ... ) but this *might* help
Please read the entire guide before attempting removal. There are many comments along the way

80’S AVION Floor repair
Purpose:
To create a guide for those repairing floor sections. These are simply guidelines; artistic and engineering improvements are of course in the fabricator’s hands.
Scope:
Removal, fabrication and reinstallation of floor sections in 80’s avion trailer floors under original or near original conditions.
Supplies:
½” plywood
¼” plywood
1 ½” foamboard
#8 x 1 ¼” screws
#9 x 1 ½” screws
2x2 poplar*
3/8” x 3 ½” Elevator bolts **
Rivets 1/8” x 1/8”
Rivets 1/8” x ¼”
Eternabond tape
Quantities vary with the scope of the project.

Tools:
Sawzall
Oscillating saw
#2 Square head bit
Skill Saw (Portable saw) plywood and rip cut blades
Drill
3/8” Drill bit
Jigsaw - various blades
¾” drill bit (Front only)
Speed square
Camera
Tape measure




A word about wood:
Poplar is a good choice and the original choice for the edges and sleepers of the floor’s construction, but that doesn’t make it the best choice. If there is a concern about repeat water intrusion, you may want to choose something more rot resistant than Poplar, such as Spanish mahogany – which is light and strong like poplar. Teak is the gold standard for rot resistance, but is heavier than either Poplar or Spanish mahogany.
Plywood:
If you feel like being deluxe, you may want to choose Okume or a Teak marine plywood. This is certainly overkill and vastly more expensive. The glues are water resistant and the wood is more rot resistant.
Failing that, a good external grade plywood from a local lumber yard is sufficient. Pressure treated requires a barrier between the aluminum and the pressure treated wood, as the chemicals used to preserve pressure treated react to the aluminum and corrode it. As such, I wouldn’t consider it ideal

Removal
Proceedure:
To understand how best to remove the floor, it is useful to understand how the floor was constructed in the first place. So, when the trailer was built, the frame was constructed, the floor laid onto the frame and then the outer skin, the wiring attached to the outer skin, insulating foam was then sprayed over that and then the interior skin was attached.
The floor on 80s’ Avions is ¼” plywood on the bottom – on top of the frame – a layer of 1 ½” foamboard and 1 ½” poplar sleepers and ½” plywood over the top.
The edges of the floor are 1 ½” poplar on the sides, center front and center rear and the radiused corners are a pair of ¾” plywood cut to shape and sandwiched between the ¼” and ½” plywood.
Before the skin is laid on, elevator bolts are used to secure the floor to the frame – around the perimeter of the floor – roughly 5/8” in from the edge.
When the outer skin was laid on, staples (Lots of them) were used to affix the bottom skin to the floor, mostly to keep the shape of the metal and conform it to the floor. These were inserted in the beltline area. The most abundant of these can be found in the radiused corners Also, staples were used to attach the U channels to the floor.
After all of that, the beltline was screwed into the floor edges.
So, the big takeaway points here are the staples and screws into the outer edges of the floor and in the U-channel, The elevator bolts on top of the floor through the floor to the frame
The staples in the radiused corners are hidden under the upper skin of the trailer – the bottom sheet metal having been attached prior to the rest.
In order to remove a section of floor, it will be necessary to remove the inner skin. In most cases this means removing any cabinetry or shelves first and then drilling out the 1/8” rivets to remove the interior skin.
Next, you will need to remove the beltline, The beltline has a piece of plastic(?) molding in its’ center which covers the screws (aptly named the screw cover) that secure it to the floor.
If your floor is original, and has the vinyl floor covering still in place, the it will be difficult to spot them from above, as the flooring is laid over them. In the very front there are four elevator bolts. At the front sides there is one elevator bolt just aft of the radius beginning. The best way to remove these is to undo the nut below the floor. However, if your floor is rotted in this area or the bolts are rusted badly, the elevator bolts will simply spin. In which case you’re left with the following options
Drill/grind the heads off the elevator bolts
Cut them off at the floor top with an oscillating saw
Grind the nuts off from underneath and push the shafts up
Split the nuts with a tool appropriately named a nut splitter and push the shafts up.
These last two methods require enough room to operate the appropriate tool and most of the time that is not an option
In the pictures below, you will see that standard bolts were used in the replacement floor. In this case, the bolts were either hidden by the skin or by cabinetry, so they were invisible.
The L brackets located periodically at the base of the shell screws into the floor. These hex head screws are frequently rusted in place. It isn’t enough to simply cut them beneath the L bracket, the remainder needs to be removed .
Installation tip. Mark the sides and the fronts of the top section of plywood for depth ie ½”. ¾”, 1” 1.5” so as you slide the wood under the U-channel, you’ll know how deep you are

When the floor is completed, before you reinstall the beltline, apply alumibond tape across the joint. Then re-attach the beltline.

[peyman.tavakolrad]

Thank you Salty. For the very useful info. So from my understanding... I'm gonna need to lift the shell up in order the get the rest of the flooring out before putting a new one?
Or is there a way to do that with out lifting the shell. I'm sorry if I'm not making sense English is my second language and sometimes I have to read things afew times to understand the whole thing.

[Salty]

you're making sense. If by lifting the shell you mean completely raising it off the frame, that is not necessary.
If I were in your position, I would start at one end and work my way back. Select a 4 or 6 foot area to replace the floor and do half of the width at a time. so, as I recall, the width of the trailer is 84 inches outer skin to outer skin (+/-) [don't take my word for it, measure your trailer] . Replace 42 inches of this width at a time.

As I see it, your biggest challenge will be to fabricate the corner radius. Most of us use the removed floor as a pattern. You don't have that luxury. Something to note. The edge of the floor is cut at a negative angle, 5 - 10 degrees, the entire floor. My point is that you have a compound curve in the corners. They are not only curved but curved and beveled.

Now that I have said all that, it may be easier for you to remove the shell to replace your floor in your particular situation. I myself have never done that, but I know people who have and it involves removing the front and rear curbside and driver side windows, passing a beam through the window openings and lifting the shell on A-frame supports. The benefit of this is that you can replace the entire floor at the same time and you can copy the shape of the corners from the raised skin by placing a piece of plywood or large piece of card board and tracing the radius.

[Salty]

looking closely at the photos you posted, you will want to address the rust issues on the frame before replacing the floor - it's easier that way.

[Pneuma1]

Oh sweet. I'm trying to think a head. I hate to have to raise the shell as I don't really have the means to do that. Right now I'm taking off the insulation with putty knife and crowbar( any suggestion on how to remove it easier is super welcome ). The rust on the frame is my next project . I've looked and asked around and some people suggested for me to use rust converter. Based on my research I came upon POR-15... Again any suggestion on alternatives is welcomed. As POR-15 is super expensive but atleast I won't need to paint afterward.

Thank you Salty.

[Pneuma1]

Also sorry for the name change I deleted my FB so I had to make another account here but I swear its me

[silverloaf]

Oh sweet. I'm trying to think a head. I hate to have to raise the shell as I don't really have the means to do that. Right now I'm taking off the insulation with putty knife and crowbar( any suggestion on how to remove it easier is super welcome ). The rust on the frame is my next project . I've looked and asked around and some people suggested for me to use rust converter. Based on my research I came upon POR-15... Again any suggestion on alternatives is welcomed. As POR-15 is super expensive but atleast I won't need to paint afterward.

Thank you Salty.

An oscillating saw (mine is made by Fein) will take it off like butter.